1. Field of the Invention
The present invention relates to a sealing plug device for a refrigerant compressor. More particularly, the present invention relates to a sealing plug device for tightly closing each of inlet and outlet ports of a refrigerant compressor so as to isolate the interior of the compressor from the atmosphere during either the storage of the compressors in a warehouse or the transporting of the compressors from e.g., the warehouse or the manufacturing factory to an automobile assembling site where the compressors are assembled in automobile refrigerating systems, for the purpose of protecting the interior of the compressor against corrosion, dirt and dust.
2. Description of the Related Art
Generally, refrigerant compressors are manufactured and assembled, as an important component of an automobile refrigerating system, in a compressor manufacturing factory. During the final stage of the assembly of respective compressors, each compressor is filled with lubricating oil used for lubricating the interior of the compressor during the operation of the compressor, and also preventing the interior of the compressor from being corroded. For example, as shown in FIG. 8, an inlet port 40a of the refrigerant compressor is formed in an outer portion of the compressor, i.e., a pipe connecting portion 40 to which suction and delivery pipes of a refrigerating system are connected.
Therefore, after the filling of the lubricating oil into the interior of the compressor, the inlet port 40a of the compressor is covered with a cap member 50 made of a rubber to seal and isolate the interior of the compressor from the atmosphere. An outlet port (not shown in FIG. 8) of the compressor is also covered by a similar cap member or a plug member. Then, the compressors are transported from the manufacturing and assembling factory to an automobile manufacturing and assembling factory where each of the compressors is assembled in an automobile refrigerating system. Namely, during the assembly of the automobile refrigerating system, the compressor is connected to a condenser and an evaporator of the refrigerating system via the suction and delivery pipes, and pipe joints. Therefore, before assembling the compressor into the refrigerating system, the cap members 50 covering the inlet port and/or the outlet port must be removed so that the suction pipe can be connected to the inlet port 40a via the pipe connector. Similarly, the delivery pipe is connected to the outlet port of the compressor via the pipe connector after the removal of the cap from the outlet port.
FIG. 9 illustrates a different cap member for closing and sealing inlet and outlet ports of a refrigerant compressor according to the prior art. The cap member 60 used for closing the suction port 40a of the pipe connecting portion 40 of the compressor is made of synthetic resin material and has a body portion 60a, an arm portion 60b laterally extending from the body portion 60a, and a hand portion 60c vertically extending from the end of the arm portion 60b. The arm portion 60b of the cap member 60 is secured to an upper portion of the connection portion 40 of the compressor by using a screw bolt 61 threadedly engaged in a threaded hole which is formed in the pipe connecting portion 40 to be inherently used for attaching a pipe joint for connecting a suction pipe to the suction port 40a when the compressor is assembled in an automobile refrigerating system. The body portion 60a of the cap member 60 is provided with a seal ring 62 fitted in an annular groove formed in the outer circumference of the body portion 60, and seals the suction port 40a of the compressor.
The afore-described cap member 50 of the prior art is securely attached to the suction port 40a of the connecting portion 40 by using only the elasticity of the cap member 50 itself, and therefore, during the transportation of the compressor, the cap member 50 might be loosened due to vibration and shocks, and eventually might come out of the suction port 40a. Further, there often occurs that the compressors must be stocked in a warehouse before they are assembled in automobile refrigerating systems for a rather long time. Thus, when the compressors are stocked, they are filled with gas to protect the interior of each compressor from dust and dirt, and corrosion. The gas used for this purpose is either helium gas or nitrogen gas which is filled into the interior of the compressors after the respective compressors are evacuated so that the pressure of the gas is higher than the atmospheric pressure. Therefore, the high pressure of the gas may cause the loosening of the cap member 50, and allows the cap member 50 to come out of the suction port 40a.
The latter cap member 60 is tightly secured to the connecting portion 40 of the compressor by the screw bolt 61, and accordingly, the cap member 60 can be surely prevented from coming out of the suction port 40a of the compressor. Nevertheless, since the cap member 60 is made of synthetic resin material having a sufficient rigidity, the needle of a syringe used for evacuating the interior of the compressor and filling the gas in the compressor cannot be easily inserted into the interior of the compressor by piercing through the cap member 60.